The use of a magnetostrictive wire waveguide to measure the position of a moveable element such as a machine tool component or a float is described in the prior art including, by way of example, U.S. Pat. No. 4,839,590 issued Jun. 13, 1989 to Richard Koski, William Kosco, and Arthur Dumais and assigned by mesne assignments to Patriot Sensors, Inc. of Clawson, Mich. In general, the magnetostrictive wire waveguide extends through the measurement field and cooperates with a toroidal "user" magnet which is moveable along and in surrounding relationship to the waveguide, the position of the user magnet being related to the position of a quantity or component being monitored. Although the specific manner of using a magnetostrictive waveguide as a position transducer may vary, the measurement function in all cases involves a determination of the time required for a sonic disturbance to propagate along the waveguide from a fixed position at or near one end of the waveguide to the user magnet or vice versa. Since the propagation speed is known, distance can be determined as a function of time.
In such devices, the accuracy of the position measurement can be seriously degraded by high frequency shocks which are transmitted to the waveguide from the outside world through the waveguide housing and support components. Such shocks and reflections thereof can be erroneously interpreted by the pickup as sonic disturbances.